Calculate the concentration of the hydrogen peroxide solution.

Question

The concentration of a hydrogen peroxide solution is determined by titrating it with a 0.1375 M solution of Ce⁴⁺. The balanced net ionic equation for the reaction is shown below.

1. 2 Ce⁴⁺(aq) +  H₂O₂(aq)+2 H₂O(l)2 Ce³⁺(aq) +  O₂(g)+2 H₃O⁺(aq)

In one experiment, 15.06 mL of the 0.1375 M Ce⁴⁺ solution is required to react completely with 40.00 mL of the hydrogen peroxide solution. Calculate the concentration of the hydrogen peroxide solution.

Answer 1

2 Ce⁴⁺(aq) +  H₂O₂(aq) + 2 H₂O(l) ==> 2 Ce³⁺(aq) +  O₂(g) + 2 H₃O⁺(aq)

mols Ce⁴⁺ used = 15.06 ml x 1 L / 1000 ml x 0.1375 mol / L = 0.002071 mols

mols H₂O₂ = 0.002071 mol Ce⁴⁺ x 1 mol H₂O₂ / 2 mol Ce⁴⁺ = 0.001036 mol H₂O₂

Concentration of H₂O₂ = 0.001036 mols / 0.0400 L = 0.02589 M (4 sig. figs.)